By Dr. Saul McLeod, updated 2019 Variables are given a special name that only applies to experimental investigations. One is called the dependent variable and the other the independent variable.
In an experiment, the researcher is looking for the possible effect on the dependent variable that might be caused by changing the independent variable. Examples of Independent and Dependent Variables in ExperimentsFor example, we might change the type of information (e.g. organized or random) given to participants to see what effect this might have on the amount of information remembered. In this particular example the type of information is the independent variable (because it changes) and the amount of information remembered is the dependent variable (because this is being measured). ActivityFor the following hypotheses name the IV and the DV. 1. Lack of sleep significantly affects learning in 10-year-old boys.IV............................................................ Operationalizing VariablesTo ensure cause and effect is established it is important that we identify exactly how the independent and dependent variables will be measured, this is known as operationalising the variables. Operational variables (or operationalizing definitions) refer to how you will define and measure a specific variable as it is used in your study. This enables another psychologist to replicate your research and is essential in establishing reliability (achieving consistency in the results). For example, if we are concerned with the effect of media violence on aggression, then we need to be very clear what we mean by the different terms. In this case, we must state what we mean by the terms “media violence” and “aggression” as we will study them. Therefore, you could state that “media violence” is operationally defined (in your experiment) as ‘exposure to a 15 minute film showing scenes of physical assault’; “aggression” is operationally defined as ‘levels of electrical shocks administered to a second ‘participant’ in another room’. In another example, the hypothesis “Young participants will have significantly better memories than older participants” is not operationalized. How do we define "young", “old” or "memory"? "Participants aged between 16 - 30 will recall significantly more nouns from a list if twenty than participants aged between 55 - 70" is operationalized. The key point here is that we have made it absolutely clear what we mean by the terms as they were studied and measured in our experiment. If we didn’t do this then it would be very difficult (if not impossible) to compare the findings of different studies into the same behavior. Operationalization has the great advantage that it generally provides a clear and objective definition of even complex variables. It also makes it easier for other researchers to replicate a study and check for reliability. ActivityFor the following hypotheses name the IV and the DV and operationalise both variables.
How to reference this article:McLeod, S. A. (2019, August 01). What are independent and dependent variables. Simply Psychology. www.simplypsychology.org/variables.html Home | About Us | Privacy Policy | Advertise | Contact Us Simply Psychology's content is for informational and educational purposes only. Our website is not intended to be a substitute for professional medical advice, diagnosis, or treatment. © Simply Scholar Ltd - All rights reserved |